Reduced tyrosine hydroxylase activity in nigrostriatal system of sinoaortic-denervated rats

Tyrosine hydroxylase activity was measured in the caudate nucleus and substantia nigra (pars compacta) of sinoaortic-denervated (SAD) and sham-operated (SO) rats 3 days after operation. The SAD groups had approximately a 50%, statistically significant, reduction of enzyme activity in both regions and also a significant reduction of dopamine in caudate nucleus. These results suggest a probable link between cortico-somatomotor integration and neural input from arterial baroreceptor neural pathways.